c292cf013d2abd1ce253507642215d68486a197d
[ghc.git] / compiler / main / GHC.hs
1 -- -----------------------------------------------------------------------------
2 --
3 -- (c) The University of Glasgow, 2005
4 --
5 -- The GHC API
6 --
7 -- -----------------------------------------------------------------------------
8
9 module GHC (
10 -- * Initialisation
11 Session,
12 defaultErrorHandler,
13 defaultCleanupHandler,
14 newSession,
15
16 -- * Flags and settings
17 DynFlags(..), DynFlag(..), Severity(..), GhcMode(..), HscTarget(..), dopt,
18 parseDynamicFlags,
19 getSessionDynFlags,
20 setSessionDynFlags,
21
22 -- * Targets
23 Target(..), TargetId(..), Phase,
24 setTargets,
25 getTargets,
26 addTarget,
27 removeTarget,
28 guessTarget,
29
30 -- * Extending the program scope
31 extendGlobalRdrScope, -- :: Session -> [GlobalRdrElt] -> IO ()
32 setGlobalRdrScope, -- :: Session -> [GlobalRdrElt] -> IO ()
33 extendGlobalTypeScope, -- :: Session -> [Id] -> IO ()
34 setGlobalTypeScope, -- :: Session -> [Id] -> IO ()
35
36 -- * Loading\/compiling the program
37 depanal,
38 load, LoadHowMuch(..), SuccessFlag(..), -- also does depanal
39 workingDirectoryChanged,
40 checkModule, CheckedModule(..),
41 TypecheckedSource, ParsedSource, RenamedSource,
42
43 -- * Parsing Haddock comments
44 parseHaddockComment,
45
46 -- * Inspecting the module structure of the program
47 ModuleGraph, ModSummary(..), ms_mod_name, ModLocation(..),
48 getModuleGraph,
49 isLoaded,
50 topSortModuleGraph,
51
52 -- * Inspecting modules
53 ModuleInfo,
54 getModuleInfo,
55 modInfoTyThings,
56 modInfoTopLevelScope,
57 modInfoPrintUnqualified,
58 modInfoExports,
59 modInfoInstances,
60 modInfoIsExportedName,
61 modInfoLookupName,
62 lookupGlobalName,
63
64 -- * Printing
65 PrintUnqualified, alwaysQualify,
66
67 -- * Interactive evaluation
68 getBindings, getPrintUnqual,
69 findModule,
70 #ifdef GHCI
71 setContext, getContext,
72 getNamesInScope,
73 getRdrNamesInScope,
74 moduleIsInterpreted,
75 getInfo,
76 exprType,
77 typeKind,
78 parseName,
79 RunResult(..),
80 runStmt,
81 showModule,
82 compileExpr, HValue, dynCompileExpr,
83 lookupName,
84
85 getBreakpointHandler, setBreakpointHandler,
86 obtainTerm,
87 #endif
88
89 -- * Abstract syntax elements
90
91 -- ** Packages
92 PackageId,
93
94 -- ** Modules
95 Module, mkModule, pprModule, moduleName, modulePackageId,
96 ModuleName, mkModuleName, moduleNameString,
97
98 -- ** Names
99 Name,
100 nameModule, pprParenSymName, nameSrcLoc,
101 NamedThing(..),
102 RdrName(Qual,Unqual),
103
104 -- ** Identifiers
105 Id, idType,
106 isImplicitId, isDeadBinder,
107 isExportedId, isLocalId, isGlobalId,
108 isRecordSelector,
109 isPrimOpId, isFCallId, isClassOpId_maybe,
110 isDataConWorkId, idDataCon,
111 isBottomingId, isDictonaryId,
112 recordSelectorFieldLabel,
113
114 -- ** Type constructors
115 TyCon,
116 tyConTyVars, tyConDataCons, tyConArity,
117 isClassTyCon, isSynTyCon, isNewTyCon, isPrimTyCon, isFunTyCon,
118 isOpenTyCon,
119 synTyConDefn, synTyConType, synTyConResKind,
120
121 -- ** Type variables
122 TyVar,
123 alphaTyVars,
124
125 -- ** Data constructors
126 DataCon,
127 dataConSig, dataConType, dataConTyCon, dataConFieldLabels,
128 dataConIsInfix, isVanillaDataCon,
129 dataConStrictMarks,
130 StrictnessMark(..), isMarkedStrict,
131
132 -- ** Classes
133 Class,
134 classMethods, classSCTheta, classTvsFds,
135 pprFundeps,
136
137 -- ** Instances
138 Instance,
139 instanceDFunId, pprInstance, pprInstanceHdr,
140
141 -- ** Types and Kinds
142 Type, dropForAlls, splitForAllTys, funResultTy, pprParendType,
143 Kind,
144 PredType,
145 ThetaType, pprThetaArrow,
146
147 -- ** Entities
148 TyThing(..),
149
150 -- ** Syntax
151 module HsSyn, -- ToDo: remove extraneous bits
152
153 -- ** Fixities
154 FixityDirection(..),
155 defaultFixity, maxPrecedence,
156 negateFixity,
157 compareFixity,
158
159 -- ** Source locations
160 SrcLoc, pprDefnLoc,
161
162 -- * Exceptions
163 GhcException(..), showGhcException,
164
165 -- * Miscellaneous
166 sessionHscEnv,
167 cyclicModuleErr,
168 ) where
169
170 {-
171 ToDo:
172
173 * inline bits of HscMain here to simplify layering: hscTcExpr, hscStmt.
174 * what StaticFlags should we expose, if any?
175 -}
176
177 #include "HsVersions.h"
178
179 #ifdef GHCI
180 import TcRnDriver ( tcRnLookupRdrName, tcRnGetInfo,
181 tcRnLookupName, getModuleExports )
182 import RdrName ( plusGlobalRdrEnv, Provenance(..),
183 ImportSpec(..), ImpDeclSpec(..), ImpItemSpec(..),
184 mkGlobalRdrEnv )
185 import HscMain ( hscParseIdentifier, hscStmt, hscTcExpr, hscKcType )
186 import Name ( nameOccName )
187 import Type ( tidyType )
188 import VarEnv ( emptyTidyEnv )
189 import GHC.Exts ( unsafeCoerce# )
190
191 -- For breakpoints
192 import Breakpoints ( SiteNumber, Coord, nullBkptHandler,
193 BkptHandler(..), BkptLocation, noDbgSites )
194 import Linker ( initDynLinker )
195 import PrelNames ( breakpointJumpName, breakpointCondJumpName,
196 breakpointAutoJumpName )
197
198 import GHC.Exts ( Int(..), Ptr(..), int2Addr#, indexArray# )
199 import GHC.Base ( Opaque(..) )
200 import Foreign.StablePtr( deRefStablePtr, castPtrToStablePtr )
201 import Foreign ( unsafePerformIO )
202 import Data.Maybe ( fromMaybe)
203 import qualified Linker
204
205 import Data.Dynamic ( Dynamic )
206 import RtClosureInspect ( cvObtainTerm, Term )
207 import Linker ( HValue, getHValue, extendLinkEnv )
208 #endif
209
210 import Packages ( initPackages )
211 import NameSet ( NameSet, nameSetToList, elemNameSet )
212 import RdrName ( GlobalRdrEnv, GlobalRdrElt(..), RdrName(..),
213 globalRdrEnvElts, extendGlobalRdrEnv,
214 emptyGlobalRdrEnv )
215 import HsSyn
216 import Type ( Kind, Type, dropForAlls, PredType, ThetaType,
217 pprThetaArrow, pprParendType, splitForAllTys,
218 funResultTy )
219 import Id ( Id, idType, isImplicitId, isDeadBinder,
220 isExportedId, isLocalId, isGlobalId,
221 isRecordSelector, recordSelectorFieldLabel,
222 isPrimOpId, isFCallId, isClassOpId_maybe,
223 isDataConWorkId, idDataCon,
224 isBottomingId )
225 import Var ( TyVar, varName )
226 import TysPrim ( alphaTyVars )
227 import TyCon ( TyCon, isClassTyCon, isSynTyCon, isNewTyCon,
228 isPrimTyCon, isFunTyCon, isOpenTyCon, tyConArity,
229 tyConTyVars, tyConDataCons, synTyConDefn,
230 synTyConType, synTyConResKind )
231 import Class ( Class, classSCTheta, classTvsFds, classMethods )
232 import FunDeps ( pprFundeps )
233 import DataCon ( DataCon, dataConWrapId, dataConSig, dataConTyCon,
234 dataConFieldLabels, dataConStrictMarks,
235 dataConIsInfix, isVanillaDataCon )
236 import Name ( Name, nameModule, NamedThing(..), nameSrcLoc )
237 import OccName ( parenSymOcc )
238 import NameEnv ( nameEnvElts )
239 import InstEnv ( Instance, instanceDFunId, pprInstance, pprInstanceHdr )
240 import SrcLoc
241 import DriverPipeline
242 import DriverPhases ( Phase(..), isHaskellSrcFilename, startPhase )
243 import HeaderInfo ( getImports, getOptions )
244 import Finder
245 import HscMain ( newHscEnv, hscFileCheck, HscChecked(..) )
246 import HscTypes
247 import DynFlags
248 import SysTools ( initSysTools, cleanTempFiles, cleanTempFilesExcept,
249 cleanTempDirs )
250 import Module
251 import UniqFM
252 import PackageConfig ( PackageId, stringToPackageId )
253 import FiniteMap
254 import Panic
255 import Digraph
256 import Bag ( unitBag, listToBag )
257 import ErrUtils ( Severity(..), showPass, fatalErrorMsg, debugTraceMsg,
258 mkPlainErrMsg, printBagOfErrors, printBagOfWarnings,
259 WarnMsg )
260 import qualified ErrUtils
261 import Util
262 import StringBuffer ( StringBuffer, hGetStringBuffer )
263 import Outputable
264 import BasicTypes
265 import TcType ( tcSplitSigmaTy, isDictTy )
266 import Maybes ( expectJust, mapCatMaybes )
267 import HaddockParse ( parseHaddockParagraphs, parseHaddockString )
268 import HaddockLex ( tokenise )
269
270 import Control.Concurrent
271 import System.Directory ( getModificationTime, doesFileExist )
272 import Data.Maybe ( isJust, isNothing )
273 import Data.List ( partition, nub )
274 import qualified Data.List as List
275 import Control.Monad ( unless, when )
276 import System.Exit ( exitWith, ExitCode(..) )
277 import System.Time ( ClockTime )
278 import Control.Exception as Exception hiding (handle)
279 import Data.IORef
280 import Data.Traversable ( traverse )
281 import System.IO
282 import System.IO.Error ( isDoesNotExistError )
283 import Prelude hiding (init)
284
285 #if __GLASGOW_HASKELL__ < 600
286 import System.IO as System.IO.Error ( try )
287 #else
288 import System.IO.Error ( try )
289 #endif
290
291 -- -----------------------------------------------------------------------------
292 -- Exception handlers
293
294 -- | Install some default exception handlers and run the inner computation.
295 -- Unless you want to handle exceptions yourself, you should wrap this around
296 -- the top level of your program. The default handlers output the error
297 -- message(s) to stderr and exit cleanly.
298 defaultErrorHandler :: DynFlags -> IO a -> IO a
299 defaultErrorHandler dflags inner =
300 -- top-level exception handler: any unrecognised exception is a compiler bug.
301 handle (\exception -> do
302 hFlush stdout
303 case exception of
304 -- an IO exception probably isn't our fault, so don't panic
305 IOException _ ->
306 fatalErrorMsg dflags (text (show exception))
307 AsyncException StackOverflow ->
308 fatalErrorMsg dflags (text "stack overflow: use +RTS -K<size> to increase it")
309 _other ->
310 fatalErrorMsg dflags (text (show (Panic (show exception))))
311 exitWith (ExitFailure 1)
312 ) $
313
314 -- program errors: messages with locations attached. Sometimes it is
315 -- convenient to just throw these as exceptions.
316 handleDyn (\dyn -> do printBagOfErrors dflags (unitBag dyn)
317 exitWith (ExitFailure 1)) $
318
319 -- error messages propagated as exceptions
320 handleDyn (\dyn -> do
321 hFlush stdout
322 case dyn of
323 PhaseFailed _ code -> exitWith code
324 Interrupted -> exitWith (ExitFailure 1)
325 _ -> do fatalErrorMsg dflags (text (show (dyn :: GhcException)))
326 exitWith (ExitFailure 1)
327 ) $
328 inner
329
330 -- | Install a default cleanup handler to remove temporary files
331 -- deposited by a GHC run. This is seperate from
332 -- 'defaultErrorHandler', because you might want to override the error
333 -- handling, but still get the ordinary cleanup behaviour.
334 defaultCleanupHandler :: DynFlags -> IO a -> IO a
335 defaultCleanupHandler dflags inner =
336 -- make sure we clean up after ourselves
337 later (unless (dopt Opt_KeepTmpFiles dflags) $
338 do cleanTempFiles dflags
339 cleanTempDirs dflags
340 )
341 -- exceptions will be blocked while we clean the temporary files,
342 -- so there shouldn't be any difficulty if we receive further
343 -- signals.
344 inner
345
346
347 #if defined(GHCI)
348 GLOBAL_VAR(v_bkptLinkEnv, [], [(Name, HValue)])
349 -- stores the current breakpoint handler to help setContext to
350 -- restore it after a context change
351 #endif
352
353 -- | Starts a new session. A session consists of a set of loaded
354 -- modules, a set of options (DynFlags), and an interactive context.
355 -- ToDo: GhcMode should say "keep typechecked code" and\/or "keep renamed
356 -- code".
357 newSession :: GhcMode -> Maybe FilePath -> IO Session
358 newSession mode mb_top_dir = do
359 -- catch ^C
360 main_thread <- myThreadId
361 modifyMVar_ interruptTargetThread (return . (main_thread :))
362 installSignalHandlers
363
364 dflags0 <- initSysTools mb_top_dir defaultDynFlags
365 dflags <- initDynFlags dflags0
366 env <- newHscEnv dflags{ ghcMode=mode }
367 ref <- newIORef env
368 return (Session ref)
369
370 -- tmp: this breaks the abstraction, but required because DriverMkDepend
371 -- needs to call the Finder. ToDo: untangle this.
372 sessionHscEnv :: Session -> IO HscEnv
373 sessionHscEnv (Session ref) = readIORef ref
374
375 withSession :: Session -> (HscEnv -> IO a) -> IO a
376 withSession (Session ref) f = do h <- readIORef ref; f h
377
378 modifySession :: Session -> (HscEnv -> HscEnv) -> IO ()
379 modifySession (Session ref) f = do h <- readIORef ref; writeIORef ref $! f h
380
381 -- -----------------------------------------------------------------------------
382 -- Flags & settings
383
384 -- | Grabs the DynFlags from the Session
385 getSessionDynFlags :: Session -> IO DynFlags
386 getSessionDynFlags s = withSession s (return . hsc_dflags)
387
388 -- | Updates the DynFlags in a Session. This also reads
389 -- the package database (unless it has already been read),
390 -- and prepares the compilers knowledge about packages. It
391 -- can be called again to load new packages: just add new
392 -- package flags to (packageFlags dflags).
393 --
394 -- Returns a list of new packages that may need to be linked in using
395 -- the dynamic linker (see 'linkPackages') as a result of new package
396 -- flags. If you are not doing linking or doing static linking, you
397 -- can ignore the list of packages returned.
398 --
399 setSessionDynFlags :: Session -> DynFlags -> IO [PackageId]
400 setSessionDynFlags (Session ref) dflags = do
401 hsc_env <- readIORef ref
402 (dflags', preload) <- initPackages dflags
403 writeIORef ref $! hsc_env{ hsc_dflags = dflags' }
404 return preload
405
406 -- | If there is no -o option, guess the name of target executable
407 -- by using top-level source file name as a base.
408 guessOutputFile :: Session -> IO ()
409 guessOutputFile s = modifySession s $ \env ->
410 let dflags = hsc_dflags env
411 mod_graph = hsc_mod_graph env
412 mainModuleSrcPath, guessedName :: Maybe String
413 mainModuleSrcPath = do
414 let isMain = (== mainModIs dflags) . ms_mod
415 [ms] <- return (filter isMain mod_graph)
416 ml_hs_file (ms_location ms)
417 guessedName = fmap basenameOf mainModuleSrcPath
418 in
419 case outputFile dflags of
420 Just _ -> env
421 Nothing -> env { hsc_dflags = dflags { outputFile = guessedName } }
422
423 -- -----------------------------------------------------------------------------
424 -- Targets
425
426 -- ToDo: think about relative vs. absolute file paths. And what
427 -- happens when the current directory changes.
428
429 -- | Sets the targets for this session. Each target may be a module name
430 -- or a filename. The targets correspond to the set of root modules for
431 -- the program\/library. Unloading the current program is achieved by
432 -- setting the current set of targets to be empty, followed by load.
433 setTargets :: Session -> [Target] -> IO ()
434 setTargets s targets = modifySession s (\h -> h{ hsc_targets = targets })
435
436 -- | returns the current set of targets
437 getTargets :: Session -> IO [Target]
438 getTargets s = withSession s (return . hsc_targets)
439
440 -- | Add another target
441 addTarget :: Session -> Target -> IO ()
442 addTarget s target
443 = modifySession s (\h -> h{ hsc_targets = target : hsc_targets h })
444
445 -- | Remove a target
446 removeTarget :: Session -> TargetId -> IO ()
447 removeTarget s target_id
448 = modifySession s (\h -> h{ hsc_targets = filter (hsc_targets h) })
449 where
450 filter targets = [ t | t@(Target id _) <- targets, id /= target_id ]
451
452 -- Attempts to guess what Target a string refers to. This function implements
453 -- the --make/GHCi command-line syntax for filenames:
454 --
455 -- - if the string looks like a Haskell source filename, then interpret
456 -- it as such
457 -- - if adding a .hs or .lhs suffix yields the name of an existing file,
458 -- then use that
459 -- - otherwise interpret the string as a module name
460 --
461 guessTarget :: String -> Maybe Phase -> IO Target
462 guessTarget file (Just phase)
463 = return (Target (TargetFile file (Just phase)) Nothing)
464 guessTarget file Nothing
465 | isHaskellSrcFilename file
466 = return (Target (TargetFile file Nothing) Nothing)
467 | otherwise
468 = do exists <- doesFileExist hs_file
469 if exists
470 then return (Target (TargetFile hs_file Nothing) Nothing)
471 else do
472 exists <- doesFileExist lhs_file
473 if exists
474 then return (Target (TargetFile lhs_file Nothing) Nothing)
475 else do
476 return (Target (TargetModule (mkModuleName file)) Nothing)
477 where
478 hs_file = file `joinFileExt` "hs"
479 lhs_file = file `joinFileExt` "lhs"
480
481 -- -----------------------------------------------------------------------------
482 -- Extending the program scope
483
484 extendGlobalRdrScope :: Session -> [GlobalRdrElt] -> IO ()
485 extendGlobalRdrScope session rdrElts
486 = modifySession session $ \hscEnv ->
487 let global_rdr = hsc_global_rdr_env hscEnv
488 in hscEnv{ hsc_global_rdr_env = foldl extendGlobalRdrEnv global_rdr rdrElts }
489
490 setGlobalRdrScope :: Session -> [GlobalRdrElt] -> IO ()
491 setGlobalRdrScope session rdrElts
492 = modifySession session $ \hscEnv ->
493 hscEnv{ hsc_global_rdr_env = foldl extendGlobalRdrEnv emptyGlobalRdrEnv rdrElts }
494
495 extendGlobalTypeScope :: Session -> [Id] -> IO ()
496 extendGlobalTypeScope session ids
497 = modifySession session $ \hscEnv ->
498 let global_type = hsc_global_type_env hscEnv
499 in hscEnv{ hsc_global_type_env = extendTypeEnvWithIds global_type ids }
500
501 setGlobalTypeScope :: Session -> [Id] -> IO ()
502 setGlobalTypeScope session ids
503 = modifySession session $ \hscEnv ->
504 hscEnv{ hsc_global_type_env = extendTypeEnvWithIds emptyTypeEnv ids }
505
506 -- -----------------------------------------------------------------------------
507 -- Parsing Haddock comments
508
509 parseHaddockComment :: String -> Either String (HsDoc RdrName)
510 parseHaddockComment string = parseHaddockParagraphs (tokenise string)
511
512 -- -----------------------------------------------------------------------------
513 -- Loading the program
514
515 -- Perform a dependency analysis starting from the current targets
516 -- and update the session with the new module graph.
517 depanal :: Session -> [ModuleName] -> Bool -> IO (Maybe ModuleGraph)
518 depanal (Session ref) excluded_mods allow_dup_roots = do
519 hsc_env <- readIORef ref
520 let
521 dflags = hsc_dflags hsc_env
522 gmode = ghcMode (hsc_dflags hsc_env)
523 targets = hsc_targets hsc_env
524 old_graph = hsc_mod_graph hsc_env
525
526 showPass dflags "Chasing dependencies"
527 when (gmode == BatchCompile) $
528 debugTraceMsg dflags 2 (hcat [
529 text "Chasing modules from: ",
530 hcat (punctuate comma (map pprTarget targets))])
531
532 r <- downsweep hsc_env old_graph excluded_mods allow_dup_roots
533 case r of
534 Just mod_graph -> writeIORef ref hsc_env{ hsc_mod_graph = mod_graph }
535 _ -> return ()
536 return r
537
538 {-
539 -- | The result of load.
540 data LoadResult
541 = LoadOk Errors -- ^ all specified targets were loaded successfully.
542 | LoadFailed Errors -- ^ not all modules were loaded.
543
544 type Errors = [String]
545
546 data ErrMsg = ErrMsg {
547 errMsgSeverity :: Severity, -- warning, error, etc.
548 errMsgSpans :: [SrcSpan],
549 errMsgShortDoc :: Doc,
550 errMsgExtraInfo :: Doc
551 }
552 -}
553
554 data LoadHowMuch
555 = LoadAllTargets
556 | LoadUpTo ModuleName
557 | LoadDependenciesOf ModuleName
558
559 -- | Try to load the program. If a Module is supplied, then just
560 -- attempt to load up to this target. If no Module is supplied,
561 -- then try to load all targets.
562 load :: Session -> LoadHowMuch -> IO SuccessFlag
563 load s@(Session ref) how_much
564 = do
565 -- Dependency analysis first. Note that this fixes the module graph:
566 -- even if we don't get a fully successful upsweep, the full module
567 -- graph is still retained in the Session. We can tell which modules
568 -- were successfully loaded by inspecting the Session's HPT.
569 mb_graph <- depanal s [] False
570 case mb_graph of
571 Just mod_graph -> load2 s how_much mod_graph
572 Nothing -> return Failed
573
574 load2 s@(Session ref) how_much mod_graph = do
575 guessOutputFile s
576 hsc_env <- readIORef ref
577
578 let hpt1 = hsc_HPT hsc_env
579 let dflags = hsc_dflags hsc_env
580 let ghci_mode = ghcMode dflags -- this never changes
581
582 -- The "bad" boot modules are the ones for which we have
583 -- B.hs-boot in the module graph, but no B.hs
584 -- The downsweep should have ensured this does not happen
585 -- (see msDeps)
586 let all_home_mods = [ms_mod_name s
587 | s <- mod_graph, not (isBootSummary s)]
588 #ifdef DEBUG
589 bad_boot_mods = [s | s <- mod_graph, isBootSummary s,
590 not (ms_mod_name s `elem` all_home_mods)]
591 #endif
592 ASSERT( null bad_boot_mods ) return ()
593
594 -- mg2_with_srcimps drops the hi-boot nodes, returning a
595 -- graph with cycles. Among other things, it is used for
596 -- backing out partially complete cycles following a failed
597 -- upsweep, and for removing from hpt all the modules
598 -- not in strict downwards closure, during calls to compile.
599 let mg2_with_srcimps :: [SCC ModSummary]
600 mg2_with_srcimps = topSortModuleGraph True mod_graph Nothing
601
602 -- If we can determine that any of the {-# SOURCE #-} imports
603 -- are definitely unnecessary, then emit a warning.
604 warnUnnecessarySourceImports dflags mg2_with_srcimps
605
606 let
607 -- check the stability property for each module.
608 stable_mods@(stable_obj,stable_bco)
609 | BatchCompile <- ghci_mode = ([],[])
610 | otherwise = checkStability hpt1 mg2_with_srcimps all_home_mods
611
612 -- prune bits of the HPT which are definitely redundant now,
613 -- to save space.
614 pruned_hpt = pruneHomePackageTable hpt1
615 (flattenSCCs mg2_with_srcimps)
616 stable_mods
617
618 evaluate pruned_hpt
619
620 debugTraceMsg dflags 2 (text "Stable obj:" <+> ppr stable_obj $$
621 text "Stable BCO:" <+> ppr stable_bco)
622
623 -- Unload any modules which are going to be re-linked this time around.
624 let stable_linkables = [ linkable
625 | m <- stable_obj++stable_bco,
626 Just hmi <- [lookupUFM pruned_hpt m],
627 Just linkable <- [hm_linkable hmi] ]
628 unload hsc_env stable_linkables
629
630 -- We could at this point detect cycles which aren't broken by
631 -- a source-import, and complain immediately, but it seems better
632 -- to let upsweep_mods do this, so at least some useful work gets
633 -- done before the upsweep is abandoned.
634 --hPutStrLn stderr "after tsort:\n"
635 --hPutStrLn stderr (showSDoc (vcat (map ppr mg2)))
636
637 -- Now do the upsweep, calling compile for each module in
638 -- turn. Final result is version 3 of everything.
639
640 -- Topologically sort the module graph, this time including hi-boot
641 -- nodes, and possibly just including the portion of the graph
642 -- reachable from the module specified in the 2nd argument to load.
643 -- This graph should be cycle-free.
644 -- If we're restricting the upsweep to a portion of the graph, we
645 -- also want to retain everything that is still stable.
646 let full_mg :: [SCC ModSummary]
647 full_mg = topSortModuleGraph False mod_graph Nothing
648
649 maybe_top_mod = case how_much of
650 LoadUpTo m -> Just m
651 LoadDependenciesOf m -> Just m
652 _ -> Nothing
653
654 partial_mg0 :: [SCC ModSummary]
655 partial_mg0 = topSortModuleGraph False mod_graph maybe_top_mod
656
657 -- LoadDependenciesOf m: we want the upsweep to stop just
658 -- short of the specified module (unless the specified module
659 -- is stable).
660 partial_mg
661 | LoadDependenciesOf mod <- how_much
662 = ASSERT( case last partial_mg0 of
663 AcyclicSCC ms -> ms_mod_name ms == mod; _ -> False )
664 List.init partial_mg0
665 | otherwise
666 = partial_mg0
667
668 stable_mg =
669 [ AcyclicSCC ms
670 | AcyclicSCC ms <- full_mg,
671 ms_mod_name ms `elem` stable_obj++stable_bco,
672 ms_mod_name ms `notElem` [ ms_mod_name ms' |
673 AcyclicSCC ms' <- partial_mg ] ]
674
675 mg = stable_mg ++ partial_mg
676
677 -- clean up between compilations
678 let cleanup = cleanTempFilesExcept dflags
679 (ppFilesFromSummaries (flattenSCCs mg2_with_srcimps))
680
681 debugTraceMsg dflags 2 (hang (text "Ready for upsweep")
682 2 (ppr mg))
683 (upsweep_ok, hsc_env1, modsUpswept)
684 <- upsweep (hsc_env { hsc_HPT = emptyHomePackageTable })
685 pruned_hpt stable_mods cleanup mg
686
687 -- Make modsDone be the summaries for each home module now
688 -- available; this should equal the domain of hpt3.
689 -- Get in in a roughly top .. bottom order (hence reverse).
690
691 let modsDone = reverse modsUpswept
692
693 -- Try and do linking in some form, depending on whether the
694 -- upsweep was completely or only partially successful.
695
696 if succeeded upsweep_ok
697
698 then
699 -- Easy; just relink it all.
700 do debugTraceMsg dflags 2 (text "Upsweep completely successful.")
701
702 -- Clean up after ourselves
703 cleanTempFilesExcept dflags (ppFilesFromSummaries modsDone)
704
705 -- Issue a warning for the confusing case where the user
706 -- said '-o foo' but we're not going to do any linking.
707 -- We attempt linking if either (a) one of the modules is
708 -- called Main, or (b) the user said -no-hs-main, indicating
709 -- that main() is going to come from somewhere else.
710 --
711 let ofile = outputFile dflags
712 let no_hs_main = dopt Opt_NoHsMain dflags
713 let
714 main_mod = mainModIs dflags
715 a_root_is_Main = any ((==main_mod).ms_mod) mod_graph
716 do_linking = a_root_is_Main || no_hs_main
717
718 when (ghci_mode == BatchCompile && isJust ofile && not do_linking) $
719 debugTraceMsg dflags 1 (text ("Warning: output was redirected with -o, " ++
720 "but no output will be generated\n" ++
721 "because there is no " ++ moduleNameString (moduleName main_mod) ++ " module."))
722
723 -- link everything together
724 linkresult <- link ghci_mode dflags do_linking (hsc_HPT hsc_env1)
725
726 loadFinish Succeeded linkresult ref hsc_env1
727
728 else
729 -- Tricky. We need to back out the effects of compiling any
730 -- half-done cycles, both so as to clean up the top level envs
731 -- and to avoid telling the interactive linker to link them.
732 do debugTraceMsg dflags 2 (text "Upsweep partially successful.")
733
734 let modsDone_names
735 = map ms_mod modsDone
736 let mods_to_zap_names
737 = findPartiallyCompletedCycles modsDone_names
738 mg2_with_srcimps
739 let mods_to_keep
740 = filter ((`notElem` mods_to_zap_names).ms_mod)
741 modsDone
742
743 let hpt4 = retainInTopLevelEnvs (map ms_mod_name mods_to_keep)
744 (hsc_HPT hsc_env1)
745
746 -- Clean up after ourselves
747 cleanTempFilesExcept dflags (ppFilesFromSummaries mods_to_keep)
748
749 -- there should be no Nothings where linkables should be, now
750 ASSERT(all (isJust.hm_linkable)
751 (eltsUFM (hsc_HPT hsc_env))) do
752
753 -- Link everything together
754 linkresult <- link ghci_mode dflags False hpt4
755
756 let hsc_env4 = hsc_env1{ hsc_HPT = hpt4 }
757 loadFinish Failed linkresult ref hsc_env4
758
759 -- Finish up after a load.
760
761 -- If the link failed, unload everything and return.
762 loadFinish all_ok Failed ref hsc_env
763 = do unload hsc_env []
764 writeIORef ref $! discardProg hsc_env
765 return Failed
766
767 -- Empty the interactive context and set the module context to the topmost
768 -- newly loaded module, or the Prelude if none were loaded.
769 loadFinish all_ok Succeeded ref hsc_env
770 = do writeIORef ref $! hsc_env{ hsc_IC = emptyInteractiveContext }
771 return all_ok
772
773
774 -- Forget the current program, but retain the persistent info in HscEnv
775 discardProg :: HscEnv -> HscEnv
776 discardProg hsc_env
777 = hsc_env { hsc_mod_graph = emptyMG,
778 hsc_IC = emptyInteractiveContext,
779 hsc_HPT = emptyHomePackageTable }
780
781 -- used to fish out the preprocess output files for the purposes of
782 -- cleaning up. The preprocessed file *might* be the same as the
783 -- source file, but that doesn't do any harm.
784 ppFilesFromSummaries summaries = map ms_hspp_file summaries
785
786 -- -----------------------------------------------------------------------------
787 -- Check module
788
789 data CheckedModule =
790 CheckedModule { parsedSource :: ParsedSource,
791 renamedSource :: Maybe RenamedSource,
792 typecheckedSource :: Maybe TypecheckedSource,
793 checkedModuleInfo :: Maybe ModuleInfo
794 }
795 -- ToDo: improvements that could be made here:
796 -- if the module succeeded renaming but not typechecking,
797 -- we can still get back the GlobalRdrEnv and exports, so
798 -- perhaps the ModuleInfo should be split up into separate
799 -- fields within CheckedModule.
800
801 type ParsedSource = Located (HsModule RdrName)
802 type RenamedSource = (HsGroup Name, [LImportDecl Name], Maybe [LIE Name],
803 Maybe (HsDoc Name), HaddockModInfo Name)
804 type TypecheckedSource = LHsBinds Id
805
806 -- NOTE:
807 -- - things that aren't in the output of the typechecker right now:
808 -- - the export list
809 -- - the imports
810 -- - type signatures
811 -- - type/data/newtype declarations
812 -- - class declarations
813 -- - instances
814 -- - extra things in the typechecker's output:
815 -- - default methods are turned into top-level decls.
816 -- - dictionary bindings
817
818
819 -- | This is the way to get access to parsed and typechecked source code
820 -- for a module. 'checkModule' loads all the dependencies of the specified
821 -- module in the Session, and then attempts to typecheck the module. If
822 -- successful, it returns the abstract syntax for the module.
823 checkModule :: Session -> ModuleName -> IO (Maybe CheckedModule)
824 checkModule session@(Session ref) mod = do
825 -- load up the dependencies first
826 r <- load session (LoadDependenciesOf mod)
827 if (failed r) then return Nothing else do
828
829 -- now parse & typecheck the module
830 hsc_env <- readIORef ref
831 let mg = hsc_mod_graph hsc_env
832 case [ ms | ms <- mg, ms_mod_name ms == mod ] of
833 [] -> return Nothing
834 (ms:_) -> do
835 mbChecked <- hscFileCheck hsc_env{hsc_dflags=ms_hspp_opts ms} ms
836 case mbChecked of
837 Nothing -> return Nothing
838 Just (HscChecked parsed renamed Nothing) ->
839 return (Just (CheckedModule {
840 parsedSource = parsed,
841 renamedSource = renamed,
842 typecheckedSource = Nothing,
843 checkedModuleInfo = Nothing }))
844 Just (HscChecked parsed renamed
845 (Just (tc_binds, rdr_env, details))) -> do
846 let minf = ModuleInfo {
847 minf_type_env = md_types details,
848 minf_exports = availsToNameSet $
849 md_exports details,
850 minf_rdr_env = Just rdr_env,
851 minf_instances = md_insts details
852 }
853 return (Just (CheckedModule {
854 parsedSource = parsed,
855 renamedSource = renamed,
856 typecheckedSource = Just tc_binds,
857 checkedModuleInfo = Just minf }))
858
859 -- ---------------------------------------------------------------------------
860 -- Unloading
861
862 unload :: HscEnv -> [Linkable] -> IO ()
863 unload hsc_env stable_linkables -- Unload everthing *except* 'stable_linkables'
864 = case ghcMode (hsc_dflags hsc_env) of
865 BatchCompile -> return ()
866 JustTypecheck -> return ()
867 #ifdef GHCI
868 Interactive -> Linker.unload (hsc_dflags hsc_env) stable_linkables
869 #else
870 Interactive -> panic "unload: no interpreter"
871 #endif
872 other -> panic "unload: strange mode"
873
874 -- -----------------------------------------------------------------------------
875 -- checkStability
876
877 {-
878 Stability tells us which modules definitely do not need to be recompiled.
879 There are two main reasons for having stability:
880
881 - avoid doing a complete upsweep of the module graph in GHCi when
882 modules near the bottom of the tree have not changed.
883
884 - to tell GHCi when it can load object code: we can only load object code
885 for a module when we also load object code fo all of the imports of the
886 module. So we need to know that we will definitely not be recompiling
887 any of these modules, and we can use the object code.
888
889 NB. stability is of no importance to BatchCompile at all, only Interactive.
890 (ToDo: what about JustTypecheck?)
891
892 The stability check is as follows. Both stableObject and
893 stableBCO are used during the upsweep phase later.
894
895 -------------------
896 stable m = stableObject m || stableBCO m
897
898 stableObject m =
899 all stableObject (imports m)
900 && old linkable does not exist, or is == on-disk .o
901 && date(on-disk .o) > date(.hs)
902
903 stableBCO m =
904 all stable (imports m)
905 && date(BCO) > date(.hs)
906 -------------------
907
908 These properties embody the following ideas:
909
910 - if a module is stable:
911 - if it has been compiled in a previous pass (present in HPT)
912 then it does not need to be compiled or re-linked.
913 - if it has not been compiled in a previous pass,
914 then we only need to read its .hi file from disk and
915 link it to produce a ModDetails.
916
917 - if a modules is not stable, we will definitely be at least
918 re-linking, and possibly re-compiling it during the upsweep.
919 All non-stable modules can (and should) therefore be unlinked
920 before the upsweep.
921
922 - Note that objects are only considered stable if they only depend
923 on other objects. We can't link object code against byte code.
924 -}
925
926 checkStability
927 :: HomePackageTable -- HPT from last compilation
928 -> [SCC ModSummary] -- current module graph (cyclic)
929 -> [ModuleName] -- all home modules
930 -> ([ModuleName], -- stableObject
931 [ModuleName]) -- stableBCO
932
933 checkStability hpt sccs all_home_mods = foldl checkSCC ([],[]) sccs
934 where
935 checkSCC (stable_obj, stable_bco) scc0
936 | stableObjects = (scc_mods ++ stable_obj, stable_bco)
937 | stableBCOs = (stable_obj, scc_mods ++ stable_bco)
938 | otherwise = (stable_obj, stable_bco)
939 where
940 scc = flattenSCC scc0
941 scc_mods = map ms_mod_name scc
942 home_module m = m `elem` all_home_mods && m `notElem` scc_mods
943
944 scc_allimps = nub (filter home_module (concatMap ms_allimps scc))
945 -- all imports outside the current SCC, but in the home pkg
946
947 stable_obj_imps = map (`elem` stable_obj) scc_allimps
948 stable_bco_imps = map (`elem` stable_bco) scc_allimps
949
950 stableObjects =
951 and stable_obj_imps
952 && all object_ok scc
953
954 stableBCOs =
955 and (zipWith (||) stable_obj_imps stable_bco_imps)
956 && all bco_ok scc
957
958 object_ok ms
959 | Just t <- ms_obj_date ms = t >= ms_hs_date ms
960 && same_as_prev t
961 | otherwise = False
962 where
963 same_as_prev t = case lookupUFM hpt (ms_mod_name ms) of
964 Just hmi | Just l <- hm_linkable hmi
965 -> isObjectLinkable l && t == linkableTime l
966 _other -> True
967 -- why '>=' rather than '>' above? If the filesystem stores
968 -- times to the nearset second, we may occasionally find that
969 -- the object & source have the same modification time,
970 -- especially if the source was automatically generated
971 -- and compiled. Using >= is slightly unsafe, but it matches
972 -- make's behaviour.
973
974 bco_ok ms
975 = case lookupUFM hpt (ms_mod_name ms) of
976 Just hmi | Just l <- hm_linkable hmi ->
977 not (isObjectLinkable l) &&
978 linkableTime l >= ms_hs_date ms
979 _other -> False
980
981 ms_allimps :: ModSummary -> [ModuleName]
982 ms_allimps ms = map unLoc (ms_srcimps ms ++ ms_imps ms)
983
984 -- -----------------------------------------------------------------------------
985 -- Prune the HomePackageTable
986
987 -- Before doing an upsweep, we can throw away:
988 --
989 -- - For non-stable modules:
990 -- - all ModDetails, all linked code
991 -- - all unlinked code that is out of date with respect to
992 -- the source file
993 --
994 -- This is VERY IMPORTANT otherwise we'll end up requiring 2x the
995 -- space at the end of the upsweep, because the topmost ModDetails of the
996 -- old HPT holds on to the entire type environment from the previous
997 -- compilation.
998
999 pruneHomePackageTable
1000 :: HomePackageTable
1001 -> [ModSummary]
1002 -> ([ModuleName],[ModuleName])
1003 -> HomePackageTable
1004
1005 pruneHomePackageTable hpt summ (stable_obj, stable_bco)
1006 = mapUFM prune hpt
1007 where prune hmi
1008 | is_stable modl = hmi'
1009 | otherwise = hmi'{ hm_details = emptyModDetails }
1010 where
1011 modl = moduleName (mi_module (hm_iface hmi))
1012 hmi' | Just l <- hm_linkable hmi, linkableTime l < ms_hs_date ms
1013 = hmi{ hm_linkable = Nothing }
1014 | otherwise
1015 = hmi
1016 where ms = expectJust "prune" (lookupUFM ms_map modl)
1017
1018 ms_map = listToUFM [(ms_mod_name ms, ms) | ms <- summ]
1019
1020 is_stable m = m `elem` stable_obj || m `elem` stable_bco
1021
1022 -- -----------------------------------------------------------------------------
1023
1024 -- Return (names of) all those in modsDone who are part of a cycle
1025 -- as defined by theGraph.
1026 findPartiallyCompletedCycles :: [Module] -> [SCC ModSummary] -> [Module]
1027 findPartiallyCompletedCycles modsDone theGraph
1028 = chew theGraph
1029 where
1030 chew [] = []
1031 chew ((AcyclicSCC v):rest) = chew rest -- acyclic? not interesting.
1032 chew ((CyclicSCC vs):rest)
1033 = let names_in_this_cycle = nub (map ms_mod vs)
1034 mods_in_this_cycle
1035 = nub ([done | done <- modsDone,
1036 done `elem` names_in_this_cycle])
1037 chewed_rest = chew rest
1038 in
1039 if notNull mods_in_this_cycle
1040 && length mods_in_this_cycle < length names_in_this_cycle
1041 then mods_in_this_cycle ++ chewed_rest
1042 else chewed_rest
1043
1044 -- -----------------------------------------------------------------------------
1045 -- The upsweep
1046
1047 -- This is where we compile each module in the module graph, in a pass
1048 -- from the bottom to the top of the graph.
1049
1050 -- There better had not be any cyclic groups here -- we check for them.
1051
1052 upsweep
1053 :: HscEnv -- Includes initially-empty HPT
1054 -> HomePackageTable -- HPT from last time round (pruned)
1055 -> ([ModuleName],[ModuleName]) -- stable modules (see checkStability)
1056 -> IO () -- How to clean up unwanted tmp files
1057 -> [SCC ModSummary] -- Mods to do (the worklist)
1058 -> IO (SuccessFlag,
1059 HscEnv, -- With an updated HPT
1060 [ModSummary]) -- Mods which succeeded
1061
1062 upsweep hsc_env old_hpt stable_mods cleanup mods
1063 = upsweep' hsc_env old_hpt stable_mods cleanup mods 1 (length mods)
1064
1065 upsweep' hsc_env old_hpt stable_mods cleanup
1066 [] _ _
1067 = return (Succeeded, hsc_env, [])
1068
1069 upsweep' hsc_env old_hpt stable_mods cleanup
1070 (CyclicSCC ms:_) _ _
1071 = do fatalErrorMsg (hsc_dflags hsc_env) (cyclicModuleErr ms)
1072 return (Failed, hsc_env, [])
1073
1074 upsweep' hsc_env old_hpt stable_mods cleanup
1075 (AcyclicSCC mod:mods) mod_index nmods
1076 = do -- putStrLn ("UPSWEEP_MOD: hpt = " ++
1077 -- show (map (moduleUserString.moduleName.mi_module.hm_iface)
1078 -- (moduleEnvElts (hsc_HPT hsc_env)))
1079
1080 mb_mod_info <- upsweep_mod hsc_env old_hpt stable_mods mod
1081 mod_index nmods
1082
1083 cleanup -- Remove unwanted tmp files between compilations
1084
1085 case mb_mod_info of
1086 Nothing -> return (Failed, hsc_env, [])
1087 Just mod_info -> do
1088 { let this_mod = ms_mod_name mod
1089
1090 -- Add new info to hsc_env
1091 hpt1 = addToUFM (hsc_HPT hsc_env) this_mod mod_info
1092 hsc_env1 = hsc_env { hsc_HPT = hpt1 }
1093
1094 -- Space-saving: delete the old HPT entry
1095 -- for mod BUT if mod is a hs-boot
1096 -- node, don't delete it. For the
1097 -- interface, the HPT entry is probaby for the
1098 -- main Haskell source file. Deleting it
1099 -- would force .. (what?? --SDM)
1100 old_hpt1 | isBootSummary mod = old_hpt
1101 | otherwise = delFromUFM old_hpt this_mod
1102
1103 ; (restOK, hsc_env2, modOKs)
1104 <- upsweep' hsc_env1 old_hpt1 stable_mods cleanup
1105 mods (mod_index+1) nmods
1106 ; return (restOK, hsc_env2, mod:modOKs)
1107 }
1108
1109
1110 -- Compile a single module. Always produce a Linkable for it if
1111 -- successful. If no compilation happened, return the old Linkable.
1112 upsweep_mod :: HscEnv
1113 -> HomePackageTable
1114 -> ([ModuleName],[ModuleName])
1115 -> ModSummary
1116 -> Int -- index of module
1117 -> Int -- total number of modules
1118 -> IO (Maybe HomeModInfo) -- Nothing => Failed
1119
1120 upsweep_mod hsc_env old_hpt (stable_obj, stable_bco) summary mod_index nmods
1121 = do
1122 let
1123 this_mod_name = ms_mod_name summary
1124 this_mod = ms_mod summary
1125 mb_obj_date = ms_obj_date summary
1126 obj_fn = ml_obj_file (ms_location summary)
1127 hs_date = ms_hs_date summary
1128
1129 compile_it :: Maybe Linkable -> IO (Maybe HomeModInfo)
1130 compile_it = upsweep_compile hsc_env old_hpt this_mod_name
1131 summary mod_index nmods
1132
1133 case ghcMode (hsc_dflags hsc_env) of
1134 BatchCompile ->
1135 case () of
1136 -- Batch-compilating is easy: just check whether we have
1137 -- an up-to-date object file. If we do, then the compiler
1138 -- needs to do a recompilation check.
1139 _ | Just obj_date <- mb_obj_date, obj_date >= hs_date -> do
1140 linkable <-
1141 findObjectLinkable this_mod obj_fn obj_date
1142 compile_it (Just linkable)
1143
1144 | otherwise ->
1145 compile_it Nothing
1146
1147 interactive ->
1148 case () of
1149 _ | is_stable_obj, isJust old_hmi ->
1150 return old_hmi
1151 -- object is stable, and we have an entry in the
1152 -- old HPT: nothing to do
1153
1154 | is_stable_obj, isNothing old_hmi -> do
1155 linkable <-
1156 findObjectLinkable this_mod obj_fn
1157 (expectJust "upseep1" mb_obj_date)
1158 compile_it (Just linkable)
1159 -- object is stable, but we need to load the interface
1160 -- off disk to make a HMI.
1161
1162 | is_stable_bco ->
1163 ASSERT(isJust old_hmi) -- must be in the old_hpt
1164 return old_hmi
1165 -- BCO is stable: nothing to do
1166
1167 | Just hmi <- old_hmi,
1168 Just l <- hm_linkable hmi, not (isObjectLinkable l),
1169 linkableTime l >= ms_hs_date summary ->
1170 compile_it (Just l)
1171 -- we have an old BCO that is up to date with respect
1172 -- to the source: do a recompilation check as normal.
1173
1174 | otherwise ->
1175 compile_it Nothing
1176 -- no existing code at all: we must recompile.
1177 where
1178 is_stable_obj = this_mod_name `elem` stable_obj
1179 is_stable_bco = this_mod_name `elem` stable_bco
1180
1181 old_hmi = lookupUFM old_hpt this_mod_name
1182
1183 -- Run hsc to compile a module
1184 upsweep_compile hsc_env old_hpt this_mod summary
1185 mod_index nmods
1186 mb_old_linkable = do
1187 let
1188 -- The old interface is ok if it's in the old HPT
1189 -- a) we're compiling a source file, and the old HPT
1190 -- entry is for a source file
1191 -- b) we're compiling a hs-boot file
1192 -- Case (b) allows an hs-boot file to get the interface of its
1193 -- real source file on the second iteration of the compilation
1194 -- manager, but that does no harm. Otherwise the hs-boot file
1195 -- will always be recompiled
1196
1197 mb_old_iface
1198 = case lookupUFM old_hpt this_mod of
1199 Nothing -> Nothing
1200 Just hm_info | isBootSummary summary -> Just iface
1201 | not (mi_boot iface) -> Just iface
1202 | otherwise -> Nothing
1203 where
1204 iface = hm_iface hm_info
1205
1206 compresult <- compile hsc_env summary mb_old_linkable mb_old_iface
1207 mod_index nmods
1208
1209 case compresult of
1210 -- Compilation failed. Compile may still have updated the PCS, tho.
1211 CompErrs -> return Nothing
1212
1213 -- Compilation "succeeded", and may or may not have returned a new
1214 -- linkable (depending on whether compilation was actually performed
1215 -- or not).
1216 CompOK new_details new_iface new_linkable
1217 -> do let new_info = HomeModInfo { hm_iface = new_iface,
1218 hm_details = new_details,
1219 hm_linkable = new_linkable }
1220 return (Just new_info)
1221
1222
1223 -- Filter modules in the HPT
1224 retainInTopLevelEnvs :: [ModuleName] -> HomePackageTable -> HomePackageTable
1225 retainInTopLevelEnvs keep_these hpt
1226 = listToUFM [ (mod, expectJust "retain" mb_mod_info)
1227 | mod <- keep_these
1228 , let mb_mod_info = lookupUFM hpt mod
1229 , isJust mb_mod_info ]
1230
1231 -- ---------------------------------------------------------------------------
1232 -- Topological sort of the module graph
1233
1234 topSortModuleGraph
1235 :: Bool -- Drop hi-boot nodes? (see below)
1236 -> [ModSummary]
1237 -> Maybe ModuleName
1238 -> [SCC ModSummary]
1239 -- Calculate SCCs of the module graph, possibly dropping the hi-boot nodes
1240 -- The resulting list of strongly-connected-components is in topologically
1241 -- sorted order, starting with the module(s) at the bottom of the
1242 -- dependency graph (ie compile them first) and ending with the ones at
1243 -- the top.
1244 --
1245 -- Drop hi-boot nodes (first boolean arg)?
1246 --
1247 -- False: treat the hi-boot summaries as nodes of the graph,
1248 -- so the graph must be acyclic
1249 --
1250 -- True: eliminate the hi-boot nodes, and instead pretend
1251 -- the a source-import of Foo is an import of Foo
1252 -- The resulting graph has no hi-boot nodes, but can by cyclic
1253
1254 topSortModuleGraph drop_hs_boot_nodes summaries Nothing
1255 = stronglyConnComp (fst (moduleGraphNodes drop_hs_boot_nodes summaries))
1256 topSortModuleGraph drop_hs_boot_nodes summaries (Just mod)
1257 = stronglyConnComp (map vertex_fn (reachable graph root))
1258 where
1259 -- restrict the graph to just those modules reachable from
1260 -- the specified module. We do this by building a graph with
1261 -- the full set of nodes, and determining the reachable set from
1262 -- the specified node.
1263 (nodes, lookup_key) = moduleGraphNodes drop_hs_boot_nodes summaries
1264 (graph, vertex_fn, key_fn) = graphFromEdges' nodes
1265 root
1266 | Just key <- lookup_key HsSrcFile mod, Just v <- key_fn key = v
1267 | otherwise = throwDyn (ProgramError "module does not exist")
1268
1269 moduleGraphNodes :: Bool -> [ModSummary]
1270 -> ([(ModSummary, Int, [Int])], HscSource -> ModuleName -> Maybe Int)
1271 moduleGraphNodes drop_hs_boot_nodes summaries = (nodes, lookup_key)
1272 where
1273 -- Drop hs-boot nodes by using HsSrcFile as the key
1274 hs_boot_key | drop_hs_boot_nodes = HsSrcFile
1275 | otherwise = HsBootFile
1276
1277 -- We use integers as the keys for the SCC algorithm
1278 nodes :: [(ModSummary, Int, [Int])]
1279 nodes = [(s, expectJust "topSort" $
1280 lookup_key (ms_hsc_src s) (ms_mod_name s),
1281 out_edge_keys hs_boot_key (map unLoc (ms_srcimps s)) ++
1282 out_edge_keys HsSrcFile (map unLoc (ms_imps s)) ++
1283 (-- see [boot-edges] below
1284 if drop_hs_boot_nodes || ms_hsc_src s == HsBootFile
1285 then []
1286 else case lookup_key HsBootFile (ms_mod_name s) of
1287 Nothing -> []
1288 Just k -> [k])
1289 )
1290 | s <- summaries
1291 , not (isBootSummary s && drop_hs_boot_nodes) ]
1292 -- Drop the hi-boot ones if told to do so
1293
1294 -- [boot-edges] if this is a .hs and there is an equivalent
1295 -- .hs-boot, add a link from the former to the latter. This
1296 -- has the effect of detecting bogus cases where the .hs-boot
1297 -- depends on the .hs, by introducing a cycle. Additionally,
1298 -- it ensures that we will always process the .hs-boot before
1299 -- the .hs, and so the HomePackageTable will always have the
1300 -- most up to date information.
1301
1302 key_map :: NodeMap Int
1303 key_map = listToFM ([(moduleName (ms_mod s), ms_hsc_src s)
1304 | s <- summaries]
1305 `zip` [1..])
1306
1307 lookup_key :: HscSource -> ModuleName -> Maybe Int
1308 lookup_key hs_src mod = lookupFM key_map (mod, hs_src)
1309
1310 out_edge_keys :: HscSource -> [ModuleName] -> [Int]
1311 out_edge_keys hi_boot ms = mapCatMaybes (lookup_key hi_boot) ms
1312 -- If we want keep_hi_boot_nodes, then we do lookup_key with
1313 -- the IsBootInterface parameter True; else False
1314
1315
1316 type NodeKey = (ModuleName, HscSource) -- The nodes of the graph are
1317 type NodeMap a = FiniteMap NodeKey a -- keyed by (mod, src_file_type) pairs
1318
1319 msKey :: ModSummary -> NodeKey
1320 msKey (ModSummary { ms_mod = mod, ms_hsc_src = boot }) = (moduleName mod,boot)
1321
1322 mkNodeMap :: [ModSummary] -> NodeMap ModSummary
1323 mkNodeMap summaries = listToFM [ (msKey s, s) | s <- summaries]
1324
1325 nodeMapElts :: NodeMap a -> [a]
1326 nodeMapElts = eltsFM
1327
1328 ms_mod_name :: ModSummary -> ModuleName
1329 ms_mod_name = moduleName . ms_mod
1330
1331 -- If there are {-# SOURCE #-} imports between strongly connected
1332 -- components in the topological sort, then those imports can
1333 -- definitely be replaced by ordinary non-SOURCE imports: if SOURCE
1334 -- were necessary, then the edge would be part of a cycle.
1335 warnUnnecessarySourceImports :: DynFlags -> [SCC ModSummary] -> IO ()
1336 warnUnnecessarySourceImports dflags sccs =
1337 printBagOfWarnings dflags (listToBag (concat (map (check.flattenSCC) sccs)))
1338 where check ms =
1339 let mods_in_this_cycle = map ms_mod_name ms in
1340 [ warn m i | m <- ms, i <- ms_srcimps m,
1341 unLoc i `notElem` mods_in_this_cycle ]
1342
1343 warn :: ModSummary -> Located ModuleName -> WarnMsg
1344 warn ms (L loc mod) =
1345 mkPlainErrMsg loc
1346 (ptext SLIT("Warning: {-# SOURCE #-} unnecessary in import of ")
1347 <+> quotes (ppr mod))
1348
1349 -----------------------------------------------------------------------------
1350 -- Downsweep (dependency analysis)
1351
1352 -- Chase downwards from the specified root set, returning summaries
1353 -- for all home modules encountered. Only follow source-import
1354 -- links.
1355
1356 -- We pass in the previous collection of summaries, which is used as a
1357 -- cache to avoid recalculating a module summary if the source is
1358 -- unchanged.
1359 --
1360 -- The returned list of [ModSummary] nodes has one node for each home-package
1361 -- module, plus one for any hs-boot files. The imports of these nodes
1362 -- are all there, including the imports of non-home-package modules.
1363
1364 downsweep :: HscEnv
1365 -> [ModSummary] -- Old summaries
1366 -> [ModuleName] -- Ignore dependencies on these; treat
1367 -- them as if they were package modules
1368 -> Bool -- True <=> allow multiple targets to have
1369 -- the same module name; this is
1370 -- very useful for ghc -M
1371 -> IO (Maybe [ModSummary])
1372 -- The elts of [ModSummary] all have distinct
1373 -- (Modules, IsBoot) identifiers, unless the Bool is true
1374 -- in which case there can be repeats
1375 downsweep hsc_env old_summaries excl_mods allow_dup_roots
1376 = -- catch error messages and return them
1377 handleDyn (\err_msg -> printBagOfErrors (hsc_dflags hsc_env) (unitBag err_msg) >> return Nothing) $ do
1378 rootSummaries <- mapM getRootSummary roots
1379 let root_map = mkRootMap rootSummaries
1380 checkDuplicates root_map
1381 summs <- loop (concatMap msDeps rootSummaries) root_map
1382 return (Just summs)
1383 where
1384 roots = hsc_targets hsc_env
1385
1386 old_summary_map :: NodeMap ModSummary
1387 old_summary_map = mkNodeMap old_summaries
1388
1389 getRootSummary :: Target -> IO ModSummary
1390 getRootSummary (Target (TargetFile file mb_phase) maybe_buf)
1391 = do exists <- doesFileExist file
1392 if exists
1393 then summariseFile hsc_env old_summaries file mb_phase maybe_buf
1394 else throwDyn $ mkPlainErrMsg noSrcSpan $
1395 text "can't find file:" <+> text file
1396 getRootSummary (Target (TargetModule modl) maybe_buf)
1397 = do maybe_summary <- summariseModule hsc_env old_summary_map False
1398 (L rootLoc modl) maybe_buf excl_mods
1399 case maybe_summary of
1400 Nothing -> packageModErr modl
1401 Just s -> return s
1402
1403 rootLoc = mkGeneralSrcSpan FSLIT("<command line>")
1404
1405 -- In a root module, the filename is allowed to diverge from the module
1406 -- name, so we have to check that there aren't multiple root files
1407 -- defining the same module (otherwise the duplicates will be silently
1408 -- ignored, leading to confusing behaviour).
1409 checkDuplicates :: NodeMap [ModSummary] -> IO ()
1410 checkDuplicates root_map
1411 | allow_dup_roots = return ()
1412 | null dup_roots = return ()
1413 | otherwise = multiRootsErr (head dup_roots)
1414 where
1415 dup_roots :: [[ModSummary]] -- Each at least of length 2
1416 dup_roots = filterOut isSingleton (nodeMapElts root_map)
1417
1418 loop :: [(Located ModuleName,IsBootInterface)]
1419 -- Work list: process these modules
1420 -> NodeMap [ModSummary]
1421 -- Visited set; the range is a list because
1422 -- the roots can have the same module names
1423 -- if allow_dup_roots is True
1424 -> IO [ModSummary]
1425 -- The result includes the worklist, except
1426 -- for those mentioned in the visited set
1427 loop [] done = return (concat (nodeMapElts done))
1428 loop ((wanted_mod, is_boot) : ss) done
1429 | Just summs <- lookupFM done key
1430 = if isSingleton summs then
1431 loop ss done
1432 else
1433 do { multiRootsErr summs; return [] }
1434 | otherwise = do { mb_s <- summariseModule hsc_env old_summary_map
1435 is_boot wanted_mod Nothing excl_mods
1436 ; case mb_s of
1437 Nothing -> loop ss done
1438 Just s -> loop (msDeps s ++ ss)
1439 (addToFM done key [s]) }
1440 where
1441 key = (unLoc wanted_mod, if is_boot then HsBootFile else HsSrcFile)
1442
1443 mkRootMap :: [ModSummary] -> NodeMap [ModSummary]
1444 mkRootMap summaries = addListToFM_C (++) emptyFM
1445 [ (msKey s, [s]) | s <- summaries ]
1446
1447 msDeps :: ModSummary -> [(Located ModuleName, IsBootInterface)]
1448 -- (msDeps s) returns the dependencies of the ModSummary s.
1449 -- A wrinkle is that for a {-# SOURCE #-} import we return
1450 -- *both* the hs-boot file
1451 -- *and* the source file
1452 -- as "dependencies". That ensures that the list of all relevant
1453 -- modules always contains B.hs if it contains B.hs-boot.
1454 -- Remember, this pass isn't doing the topological sort. It's
1455 -- just gathering the list of all relevant ModSummaries
1456 msDeps s =
1457 concat [ [(m,True), (m,False)] | m <- ms_srcimps s ]
1458 ++ [ (m,False) | m <- ms_imps s ]
1459
1460 -----------------------------------------------------------------------------
1461 -- Summarising modules
1462
1463 -- We have two types of summarisation:
1464 --
1465 -- * Summarise a file. This is used for the root module(s) passed to
1466 -- cmLoadModules. The file is read, and used to determine the root
1467 -- module name. The module name may differ from the filename.
1468 --
1469 -- * Summarise a module. We are given a module name, and must provide
1470 -- a summary. The finder is used to locate the file in which the module
1471 -- resides.
1472
1473 summariseFile
1474 :: HscEnv
1475 -> [ModSummary] -- old summaries
1476 -> FilePath -- source file name
1477 -> Maybe Phase -- start phase
1478 -> Maybe (StringBuffer,ClockTime)
1479 -> IO ModSummary
1480
1481 summariseFile hsc_env old_summaries file mb_phase maybe_buf
1482 -- we can use a cached summary if one is available and the
1483 -- source file hasn't changed, But we have to look up the summary
1484 -- by source file, rather than module name as we do in summarise.
1485 | Just old_summary <- findSummaryBySourceFile old_summaries file
1486 = do
1487 let location = ms_location old_summary
1488
1489 -- return the cached summary if the source didn't change
1490 src_timestamp <- case maybe_buf of
1491 Just (_,t) -> return t
1492 Nothing -> getModificationTime file
1493 -- The file exists; we checked in getRootSummary above.
1494 -- If it gets removed subsequently, then this
1495 -- getModificationTime may fail, but that's the right
1496 -- behaviour.
1497
1498 if ms_hs_date old_summary == src_timestamp
1499 then do -- update the object-file timestamp
1500 obj_timestamp <- getObjTimestamp location False
1501 return old_summary{ ms_obj_date = obj_timestamp }
1502 else
1503 new_summary
1504
1505 | otherwise
1506 = new_summary
1507 where
1508 new_summary = do
1509 let dflags = hsc_dflags hsc_env
1510
1511 (dflags', hspp_fn, buf)
1512 <- preprocessFile dflags file mb_phase maybe_buf
1513
1514 (srcimps,the_imps, L _ mod_name) <- getImports dflags' buf hspp_fn
1515
1516 -- Make a ModLocation for this file
1517 location <- mkHomeModLocation dflags mod_name file
1518
1519 -- Tell the Finder cache where it is, so that subsequent calls
1520 -- to findModule will find it, even if it's not on any search path
1521 mod <- addHomeModuleToFinder hsc_env mod_name location
1522
1523 src_timestamp <- case maybe_buf of
1524 Just (_,t) -> return t
1525 Nothing -> getModificationTime file
1526 -- getMofificationTime may fail
1527
1528 obj_timestamp <- modificationTimeIfExists (ml_obj_file location)
1529
1530 return (ModSummary { ms_mod = mod, ms_hsc_src = HsSrcFile,
1531 ms_location = location,
1532 ms_hspp_file = hspp_fn,
1533 ms_hspp_opts = dflags',
1534 ms_hspp_buf = Just buf,
1535 ms_srcimps = srcimps, ms_imps = the_imps,
1536 ms_hs_date = src_timestamp,
1537 ms_obj_date = obj_timestamp })
1538
1539 findSummaryBySourceFile :: [ModSummary] -> FilePath -> Maybe ModSummary
1540 findSummaryBySourceFile summaries file
1541 = case [ ms | ms <- summaries, HsSrcFile <- [ms_hsc_src ms],
1542 expectJust "findSummaryBySourceFile" (ml_hs_file (ms_location ms)) == file ] of
1543 [] -> Nothing
1544 (x:xs) -> Just x
1545
1546 -- Summarise a module, and pick up source and timestamp.
1547 summariseModule
1548 :: HscEnv
1549 -> NodeMap ModSummary -- Map of old summaries
1550 -> IsBootInterface -- True <=> a {-# SOURCE #-} import
1551 -> Located ModuleName -- Imported module to be summarised
1552 -> Maybe (StringBuffer, ClockTime)
1553 -> [ModuleName] -- Modules to exclude
1554 -> IO (Maybe ModSummary) -- Its new summary
1555
1556 summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod) maybe_buf excl_mods
1557 | wanted_mod `elem` excl_mods
1558 = return Nothing
1559
1560 | Just old_summary <- lookupFM old_summary_map (wanted_mod, hsc_src)
1561 = do -- Find its new timestamp; all the
1562 -- ModSummaries in the old map have valid ml_hs_files
1563 let location = ms_location old_summary
1564 src_fn = expectJust "summariseModule" (ml_hs_file location)
1565
1566 -- check the modification time on the source file, and
1567 -- return the cached summary if it hasn't changed. If the
1568 -- file has disappeared, we need to call the Finder again.
1569 case maybe_buf of
1570 Just (_,t) -> check_timestamp old_summary location src_fn t
1571 Nothing -> do
1572 m <- System.IO.Error.try (getModificationTime src_fn)
1573 case m of
1574 Right t -> check_timestamp old_summary location src_fn t
1575 Left e | isDoesNotExistError e -> find_it
1576 | otherwise -> ioError e
1577
1578 | otherwise = find_it
1579 where
1580 dflags = hsc_dflags hsc_env
1581
1582 hsc_src = if is_boot then HsBootFile else HsSrcFile
1583
1584 check_timestamp old_summary location src_fn src_timestamp
1585 | ms_hs_date old_summary == src_timestamp = do
1586 -- update the object-file timestamp
1587 obj_timestamp <- getObjTimestamp location is_boot
1588 return (Just old_summary{ ms_obj_date = obj_timestamp })
1589 | otherwise =
1590 -- source changed: re-summarise.
1591 new_summary location (ms_mod old_summary) src_fn src_timestamp
1592
1593 find_it = do
1594 -- Don't use the Finder's cache this time. If the module was
1595 -- previously a package module, it may have now appeared on the
1596 -- search path, so we want to consider it to be a home module. If
1597 -- the module was previously a home module, it may have moved.
1598 uncacheModule hsc_env wanted_mod
1599 found <- findImportedModule hsc_env wanted_mod Nothing
1600 case found of
1601 Found location mod
1602 | isJust (ml_hs_file location) ->
1603 -- Home package
1604 just_found location mod
1605 | otherwise ->
1606 -- Drop external-pkg
1607 ASSERT(modulePackageId mod /= thisPackage dflags)
1608 return Nothing
1609 where
1610
1611 err -> noModError dflags loc wanted_mod err
1612 -- Not found
1613
1614 just_found location mod = do
1615 -- Adjust location to point to the hs-boot source file,
1616 -- hi file, object file, when is_boot says so
1617 let location' | is_boot = addBootSuffixLocn location
1618 | otherwise = location
1619 src_fn = expectJust "summarise2" (ml_hs_file location')
1620
1621 -- Check that it exists
1622 -- It might have been deleted since the Finder last found it
1623 maybe_t <- modificationTimeIfExists src_fn
1624 case maybe_t of
1625 Nothing -> noHsFileErr loc src_fn
1626 Just t -> new_summary location' mod src_fn t
1627
1628
1629 new_summary location mod src_fn src_timestamp
1630 = do
1631 -- Preprocess the source file and get its imports
1632 -- The dflags' contains the OPTIONS pragmas
1633 (dflags', hspp_fn, buf) <- preprocessFile dflags src_fn Nothing maybe_buf
1634 (srcimps, the_imps, L mod_loc mod_name) <- getImports dflags' buf hspp_fn
1635
1636 when (mod_name /= wanted_mod) $
1637 throwDyn $ mkPlainErrMsg mod_loc $
1638 text "file name does not match module name"
1639 <+> quotes (ppr mod_name)
1640
1641 -- Find the object timestamp, and return the summary
1642 obj_timestamp <- getObjTimestamp location is_boot
1643
1644 return (Just ( ModSummary { ms_mod = mod,
1645 ms_hsc_src = hsc_src,
1646 ms_location = location,
1647 ms_hspp_file = hspp_fn,
1648 ms_hspp_opts = dflags',
1649 ms_hspp_buf = Just buf,
1650 ms_srcimps = srcimps,
1651 ms_imps = the_imps,
1652 ms_hs_date = src_timestamp,
1653 ms_obj_date = obj_timestamp }))
1654
1655
1656 getObjTimestamp location is_boot
1657 = if is_boot then return Nothing
1658 else modificationTimeIfExists (ml_obj_file location)
1659
1660
1661 preprocessFile :: DynFlags -> FilePath -> Maybe Phase -> Maybe (StringBuffer,ClockTime)
1662 -> IO (DynFlags, FilePath, StringBuffer)
1663 preprocessFile dflags src_fn mb_phase Nothing
1664 = do
1665 (dflags', hspp_fn) <- preprocess dflags (src_fn, mb_phase)
1666 buf <- hGetStringBuffer hspp_fn
1667 return (dflags', hspp_fn, buf)
1668
1669 preprocessFile dflags src_fn mb_phase (Just (buf, time))
1670 = do
1671 -- case we bypass the preprocessing stage?
1672 let
1673 local_opts = getOptions buf src_fn
1674 --
1675 (dflags', errs) <- parseDynamicFlags dflags (map unLoc local_opts)
1676
1677 let
1678 needs_preprocessing
1679 | Just (Unlit _) <- mb_phase = True
1680 | Nothing <- mb_phase, Unlit _ <- startPhase src_fn = True
1681 -- note: local_opts is only required if there's no Unlit phase
1682 | dopt Opt_Cpp dflags' = True
1683 | dopt Opt_Pp dflags' = True
1684 | otherwise = False
1685
1686 when needs_preprocessing $
1687 ghcError (ProgramError "buffer needs preprocesing; interactive check disabled")
1688
1689 return (dflags', src_fn, buf)
1690
1691
1692 -----------------------------------------------------------------------------
1693 -- Error messages
1694 -----------------------------------------------------------------------------
1695
1696 noModError :: DynFlags -> SrcSpan -> ModuleName -> FindResult -> IO ab
1697 -- ToDo: we don't have a proper line number for this error
1698 noModError dflags loc wanted_mod err
1699 = throwDyn $ mkPlainErrMsg loc $ cannotFindModule dflags wanted_mod err
1700
1701 noHsFileErr loc path
1702 = throwDyn $ mkPlainErrMsg loc $ text "Can't find" <+> text path
1703
1704 packageModErr mod
1705 = throwDyn $ mkPlainErrMsg noSrcSpan $
1706 text "module" <+> quotes (ppr mod) <+> text "is a package module"
1707
1708 multiRootsErr :: [ModSummary] -> IO ()
1709 multiRootsErr summs@(summ1:_)
1710 = throwDyn $ mkPlainErrMsg noSrcSpan $
1711 text "module" <+> quotes (ppr mod) <+>
1712 text "is defined in multiple files:" <+>
1713 sep (map text files)
1714 where
1715 mod = ms_mod summ1
1716 files = map (expectJust "checkDup" . ml_hs_file . ms_location) summs
1717
1718 cyclicModuleErr :: [ModSummary] -> SDoc
1719 cyclicModuleErr ms
1720 = hang (ptext SLIT("Module imports form a cycle for modules:"))
1721 2 (vcat (map show_one ms))
1722 where
1723 show_one ms = sep [ show_mod (ms_hsc_src ms) (ms_mod ms),
1724 nest 2 $ ptext SLIT("imports:") <+>
1725 (pp_imps HsBootFile (ms_srcimps ms)
1726 $$ pp_imps HsSrcFile (ms_imps ms))]
1727 show_mod hsc_src mod = ppr mod <> text (hscSourceString hsc_src)
1728 pp_imps src mods = fsep (map (show_mod src) mods)
1729
1730
1731 -- | Inform GHC that the working directory has changed. GHC will flush
1732 -- its cache of module locations, since it may no longer be valid.
1733 -- Note: if you change the working directory, you should also unload
1734 -- the current program (set targets to empty, followed by load).
1735 workingDirectoryChanged :: Session -> IO ()
1736 workingDirectoryChanged s = withSession s $ flushFinderCaches
1737
1738 -- -----------------------------------------------------------------------------
1739 -- inspecting the session
1740
1741 -- | Get the module dependency graph.
1742 getModuleGraph :: Session -> IO ModuleGraph -- ToDo: DiGraph ModSummary
1743 getModuleGraph s = withSession s (return . hsc_mod_graph)
1744
1745 isLoaded :: Session -> ModuleName -> IO Bool
1746 isLoaded s m = withSession s $ \hsc_env ->
1747 return $! isJust (lookupUFM (hsc_HPT hsc_env) m)
1748
1749 getBindings :: Session -> IO [TyThing]
1750 getBindings s = withSession s (return . nameEnvElts . ic_type_env . hsc_IC)
1751
1752 getPrintUnqual :: Session -> IO PrintUnqualified
1753 getPrintUnqual s = withSession s (return . icPrintUnqual . hsc_IC)
1754
1755 -- | Container for information about a 'Module'.
1756 data ModuleInfo = ModuleInfo {
1757 minf_type_env :: TypeEnv,
1758 minf_exports :: NameSet, -- ToDo, [AvailInfo] like ModDetails?
1759 minf_rdr_env :: Maybe GlobalRdrEnv, -- Nothing for a compiled/package mod
1760 minf_instances :: [Instance]
1761 -- ToDo: this should really contain the ModIface too
1762 }
1763 -- We don't want HomeModInfo here, because a ModuleInfo applies
1764 -- to package modules too.
1765
1766 -- | Request information about a loaded 'Module'
1767 getModuleInfo :: Session -> Module -> IO (Maybe ModuleInfo)
1768 getModuleInfo s mdl = withSession s $ \hsc_env -> do
1769 let mg = hsc_mod_graph hsc_env
1770 if mdl `elem` map ms_mod mg
1771 then getHomeModuleInfo hsc_env (moduleName mdl)
1772 else do
1773 {- if isHomeModule (hsc_dflags hsc_env) mdl
1774 then return Nothing
1775 else -} getPackageModuleInfo hsc_env mdl
1776 -- getPackageModuleInfo will attempt to find the interface, so
1777 -- we don't want to call it for a home module, just in case there
1778 -- was a problem loading the module and the interface doesn't
1779 -- exist... hence the isHomeModule test here. (ToDo: reinstate)
1780
1781 getPackageModuleInfo :: HscEnv -> Module -> IO (Maybe ModuleInfo)
1782 getPackageModuleInfo hsc_env mdl = do
1783 #ifdef GHCI
1784 (_msgs, mb_avails) <- getModuleExports hsc_env mdl
1785 case mb_avails of
1786 Nothing -> return Nothing
1787 Just avails -> do
1788 eps <- readIORef (hsc_EPS hsc_env)
1789 let
1790 names = availsToNameSet avails
1791 pte = eps_PTE eps
1792 tys = [ ty | name <- concatMap availNames avails,
1793 Just ty <- [lookupTypeEnv pte name] ]
1794 --
1795 return (Just (ModuleInfo {
1796 minf_type_env = mkTypeEnv tys,
1797 minf_exports = names,
1798 minf_rdr_env = Just $! nameSetToGlobalRdrEnv names (moduleName mdl),
1799 minf_instances = error "getModuleInfo: instances for package module unimplemented"
1800 }))
1801 #else
1802 -- bogusly different for non-GHCI (ToDo)
1803 return Nothing
1804 #endif
1805
1806 getHomeModuleInfo hsc_env mdl =
1807 case lookupUFM (hsc_HPT hsc_env) mdl of
1808 Nothing -> return Nothing
1809 Just hmi -> do
1810 let details = hm_details hmi
1811 return (Just (ModuleInfo {
1812 minf_type_env = md_types details,
1813 minf_exports = availsToNameSet (md_exports details),
1814 minf_rdr_env = mi_globals $! hm_iface hmi,
1815 minf_instances = md_insts details
1816 }))
1817
1818 -- | The list of top-level entities defined in a module
1819 modInfoTyThings :: ModuleInfo -> [TyThing]
1820 modInfoTyThings minf = typeEnvElts (minf_type_env minf)
1821
1822 modInfoTopLevelScope :: ModuleInfo -> Maybe [Name]
1823 modInfoTopLevelScope minf
1824 = fmap (map gre_name . globalRdrEnvElts) (minf_rdr_env minf)
1825
1826 modInfoExports :: ModuleInfo -> [Name]
1827 modInfoExports minf = nameSetToList $! minf_exports minf
1828
1829 -- | Returns the instances defined by the specified module.
1830 -- Warning: currently unimplemented for package modules.
1831 modInfoInstances :: ModuleInfo -> [Instance]
1832 modInfoInstances = minf_instances
1833
1834 modInfoIsExportedName :: ModuleInfo -> Name -> Bool
1835 modInfoIsExportedName minf name = elemNameSet name (minf_exports minf)
1836
1837 modInfoPrintUnqualified :: ModuleInfo -> Maybe PrintUnqualified
1838 modInfoPrintUnqualified minf = fmap mkPrintUnqualified (minf_rdr_env minf)
1839
1840 modInfoLookupName :: Session -> ModuleInfo -> Name -> IO (Maybe TyThing)
1841 modInfoLookupName s minf name = withSession s $ \hsc_env -> do
1842 case lookupTypeEnv (minf_type_env minf) name of
1843 Just tyThing -> return (Just tyThing)
1844 Nothing -> do
1845 eps <- readIORef (hsc_EPS hsc_env)
1846 return $! lookupType (hsc_dflags hsc_env)
1847 (hsc_HPT hsc_env) (eps_PTE eps) name
1848
1849 isDictonaryId :: Id -> Bool
1850 isDictonaryId id
1851 = case tcSplitSigmaTy (idType id) of { (tvs, theta, tau) -> isDictTy tau }
1852
1853 -- | Looks up a global name: that is, any top-level name in any
1854 -- visible module. Unlike 'lookupName', lookupGlobalName does not use
1855 -- the interactive context, and therefore does not require a preceding
1856 -- 'setContext'.
1857 lookupGlobalName :: Session -> Name -> IO (Maybe TyThing)
1858 lookupGlobalName s name = withSession s $ \hsc_env -> do
1859 eps <- readIORef (hsc_EPS hsc_env)
1860 return $! lookupType (hsc_dflags hsc_env)
1861 (hsc_HPT hsc_env) (eps_PTE eps) name
1862
1863 -- -----------------------------------------------------------------------------
1864 -- Misc exported utils
1865
1866 dataConType :: DataCon -> Type
1867 dataConType dc = idType (dataConWrapId dc)
1868
1869 -- | print a 'NamedThing', adding parentheses if the name is an operator.
1870 pprParenSymName :: NamedThing a => a -> SDoc
1871 pprParenSymName a = parenSymOcc (getOccName a) (ppr (getName a))
1872
1873 -- ----------------------------------------------------------------------------
1874
1875 #if 0
1876
1877 -- ToDo:
1878 -- - Data and Typeable instances for HsSyn.
1879
1880 -- ToDo: check for small transformations that happen to the syntax in
1881 -- the typechecker (eg. -e ==> negate e, perhaps for fromIntegral)
1882
1883 -- ToDo: maybe use TH syntax instead of IfaceSyn? There's already a way
1884 -- to get from TyCons, Ids etc. to TH syntax (reify).
1885
1886 -- :browse will use either lm_toplev or inspect lm_interface, depending
1887 -- on whether the module is interpreted or not.
1888
1889 -- This is for reconstructing refactored source code
1890 -- Calls the lexer repeatedly.
1891 -- ToDo: add comment tokens to token stream
1892 getTokenStream :: Session -> Module -> IO [Located Token]
1893 #endif
1894
1895 -- -----------------------------------------------------------------------------
1896 -- Interactive evaluation
1897
1898 -- | Takes a 'ModuleName' and possibly a 'PackageId', and consults the
1899 -- filesystem and package database to find the corresponding 'Module',
1900 -- using the algorithm that is used for an @import@ declaration.
1901 findModule :: Session -> ModuleName -> Maybe PackageId -> IO Module
1902 findModule s mod_name maybe_pkg = withSession s $ \hsc_env ->
1903 findModule' hsc_env mod_name maybe_pkg
1904
1905 findModule' hsc_env mod_name maybe_pkg =
1906 let
1907 dflags = hsc_dflags hsc_env
1908 hpt = hsc_HPT hsc_env
1909 this_pkg = thisPackage dflags
1910 in
1911 case lookupUFM hpt mod_name of
1912 Just mod_info -> return (mi_module (hm_iface mod_info))
1913 _not_a_home_module -> do
1914 res <- findImportedModule hsc_env mod_name Nothing
1915 case res of
1916 Found _ m | modulePackageId m /= this_pkg -> return m
1917 | otherwise -> throwDyn (CmdLineError (showSDoc $
1918 text "module" <+> pprModule m <+>
1919 text "is not loaded"))
1920 err -> let msg = cannotFindModule dflags mod_name err in
1921 throwDyn (CmdLineError (showSDoc msg))
1922
1923 #ifdef GHCI
1924
1925 -- | Set the interactive evaluation context.
1926 --
1927 -- Setting the context doesn't throw away any bindings; the bindings
1928 -- we've built up in the InteractiveContext simply move to the new
1929 -- module. They always shadow anything in scope in the current context.
1930 setContext :: Session
1931 -> [Module] -- entire top level scope of these modules
1932 -> [Module] -- exports only of these modules
1933 -> IO ()
1934 setContext sess@(Session ref) toplev_mods export_mods = do
1935 hsc_env <- readIORef ref
1936 let old_ic = hsc_IC hsc_env
1937 hpt = hsc_HPT hsc_env
1938 --
1939 export_env <- mkExportEnv hsc_env export_mods
1940 toplev_envs <- mapM (mkTopLevEnv hpt) toplev_mods
1941 let all_env = foldr plusGlobalRdrEnv export_env toplev_envs
1942 writeIORef ref hsc_env{ hsc_IC = old_ic { ic_toplev_scope = toplev_mods,
1943 ic_exports = export_mods,
1944 ic_rn_gbl_env = all_env }}
1945 reinstallBreakpointHandlers sess
1946
1947 -- Make a GlobalRdrEnv based on the exports of the modules only.
1948 mkExportEnv :: HscEnv -> [Module] -> IO GlobalRdrEnv
1949 mkExportEnv hsc_env mods = do
1950 stuff <- mapM (getModuleExports hsc_env) mods
1951 let
1952 (_msgs, mb_name_sets) = unzip stuff
1953 gres = [ nameSetToGlobalRdrEnv (availsToNameSet avails) (moduleName mod)
1954 | (Just avails, mod) <- zip mb_name_sets mods ]
1955 --
1956 return $! foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres
1957
1958 nameSetToGlobalRdrEnv :: NameSet -> ModuleName -> GlobalRdrEnv
1959 nameSetToGlobalRdrEnv names mod =
1960 mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = vanillaProv mod }
1961 | name <- nameSetToList names ]
1962
1963 vanillaProv :: ModuleName -> Provenance
1964 -- We're building a GlobalRdrEnv as if the user imported
1965 -- all the specified modules into the global interactive module
1966 vanillaProv mod_name = Imported [ImpSpec { is_decl = decl, is_item = ImpAll}]
1967 where
1968 decl = ImpDeclSpec { is_mod = mod_name, is_as = mod_name,
1969 is_qual = False,
1970 is_dloc = srcLocSpan interactiveSrcLoc }
1971
1972 mkTopLevEnv :: HomePackageTable -> Module -> IO GlobalRdrEnv
1973 mkTopLevEnv hpt modl
1974 = case lookupUFM hpt (moduleName modl) of
1975 Nothing -> throwDyn (ProgramError ("mkTopLevEnv: not a home module " ++
1976 showSDoc (ppr modl)))
1977 Just details ->
1978 case mi_globals (hm_iface details) of
1979 Nothing ->
1980 throwDyn (ProgramError ("mkTopLevEnv: not interpreted "
1981 ++ showSDoc (ppr modl)))
1982 Just env -> return env
1983
1984 -- | Get the interactive evaluation context, consisting of a pair of the
1985 -- set of modules from which we take the full top-level scope, and the set
1986 -- of modules from which we take just the exports respectively.
1987 getContext :: Session -> IO ([Module],[Module])
1988 getContext s = withSession s (\HscEnv{ hsc_IC=ic } ->
1989 return (ic_toplev_scope ic, ic_exports ic))
1990
1991 -- | Returns 'True' if the specified module is interpreted, and hence has
1992 -- its full top-level scope available.
1993 moduleIsInterpreted :: Session -> Module -> IO Bool
1994 moduleIsInterpreted s modl = withSession s $ \h ->
1995 if modulePackageId modl /= thisPackage (hsc_dflags h)
1996 then return False
1997 else case lookupUFM (hsc_HPT h) (moduleName modl) of
1998 Just details -> return (isJust (mi_globals (hm_iface details)))
1999 _not_a_home_module -> return False
2000
2001 -- | Looks up an identifier in the current interactive context (for :info)
2002 getInfo :: Session -> Name -> IO (Maybe (TyThing,Fixity,[Instance]))
2003 getInfo s name = withSession s $ \hsc_env -> tcRnGetInfo hsc_env name
2004
2005 -- | Returns all names in scope in the current interactive context
2006 getNamesInScope :: Session -> IO [Name]
2007 getNamesInScope s = withSession s $ \hsc_env -> do
2008 return (map gre_name (globalRdrEnvElts (ic_rn_gbl_env (hsc_IC hsc_env))))
2009
2010 getRdrNamesInScope :: Session -> IO [RdrName]
2011 getRdrNamesInScope s = withSession s $ \hsc_env -> do
2012 let env = ic_rn_gbl_env (hsc_IC hsc_env)
2013 return (concat (map greToRdrNames (globalRdrEnvElts env)))
2014
2015 -- ToDo: move to RdrName
2016 greToRdrNames :: GlobalRdrElt -> [RdrName]
2017 greToRdrNames GRE{ gre_name = name, gre_prov = prov }
2018 = case prov of
2019 LocalDef -> [unqual]
2020 Imported specs -> concat (map do_spec (map is_decl specs))
2021 where
2022 occ = nameOccName name
2023 unqual = Unqual occ
2024 do_spec decl_spec
2025 | is_qual decl_spec = [qual]
2026 | otherwise = [unqual,qual]
2027 where qual = Qual (is_as decl_spec) occ
2028
2029 -- | Parses a string as an identifier, and returns the list of 'Name's that
2030 -- the identifier can refer to in the current interactive context.
2031 parseName :: Session -> String -> IO [Name]
2032 parseName s str = withSession s $ \hsc_env -> do
2033 maybe_rdr_name <- hscParseIdentifier (hsc_dflags hsc_env) str
2034 case maybe_rdr_name of
2035 Nothing -> return []
2036 Just (L _ rdr_name) -> do
2037 mb_names <- tcRnLookupRdrName hsc_env rdr_name
2038 case mb_names of
2039 Nothing -> return []
2040 Just ns -> return ns
2041 -- ToDo: should return error messages
2042
2043 -- | Returns the 'TyThing' for a 'Name'. The 'Name' may refer to any
2044 -- entity known to GHC, including 'Name's defined using 'runStmt'.
2045 lookupName :: Session -> Name -> IO (Maybe TyThing)
2046 lookupName s name = withSession s $ \hsc_env -> tcRnLookupName hsc_env name
2047
2048 -- -----------------------------------------------------------------------------
2049 -- Getting the type of an expression
2050
2051 -- | Get the type of an expression
2052 exprType :: Session -> String -> IO (Maybe Type)
2053 exprType s expr = withSession s $ \hsc_env -> do
2054 maybe_stuff <- hscTcExpr hsc_env expr
2055 case maybe_stuff of
2056 Nothing -> return Nothing
2057 Just ty -> return (Just tidy_ty)
2058 where
2059 tidy_ty = tidyType emptyTidyEnv ty
2060
2061 -- -----------------------------------------------------------------------------
2062 -- Getting the kind of a type
2063
2064 -- | Get the kind of a type
2065 typeKind :: Session -> String -> IO (Maybe Kind)
2066 typeKind s str = withSession s $ \hsc_env -> do
2067 maybe_stuff <- hscKcType hsc_env str
2068 case maybe_stuff of
2069 Nothing -> return Nothing
2070 Just kind -> return (Just kind)
2071
2072 -----------------------------------------------------------------------------
2073 -- cmCompileExpr: compile an expression and deliver an HValue
2074
2075 compileExpr :: Session -> String -> IO (Maybe HValue)
2076 compileExpr s expr = withSession s $ \hsc_env -> do
2077 maybe_stuff <- hscStmt hsc_env ("let __cmCompileExpr = "++expr)
2078 case maybe_stuff of
2079 Nothing -> return Nothing
2080 Just (new_ic, names, hval) -> do
2081 -- Run it!
2082 hvals <- (unsafeCoerce# hval) :: IO [HValue]
2083
2084 case (names,hvals) of
2085 ([n],[hv]) -> return (Just hv)
2086 _ -> panic "compileExpr"
2087
2088 -- -----------------------------------------------------------------------------
2089 -- Compile an expression into a dynamic
2090
2091 dynCompileExpr :: Session -> String -> IO (Maybe Dynamic)
2092 dynCompileExpr ses expr = do
2093 (full,exports) <- getContext ses
2094 setContext ses full $
2095 (mkModule
2096 (stringToPackageId "base") (mkModuleName "Data.Dynamic")
2097 ):exports
2098 let stmt = "let __dynCompileExpr = Data.Dynamic.toDyn (" ++ expr ++ ")"
2099 res <- withSession ses (flip hscStmt stmt)
2100 setContext ses full exports
2101 case res of
2102 Nothing -> return Nothing
2103 Just (_, names, hvals) -> do
2104 vals <- (unsafeCoerce# hvals :: IO [Dynamic])
2105 case (names,vals) of
2106 (_:[], v:[]) -> return (Just v)
2107 _ -> panic "dynCompileExpr"
2108
2109 -- -----------------------------------------------------------------------------
2110 -- running a statement interactively
2111
2112 data RunResult
2113 = RunOk [Name] -- ^ names bound by this evaluation
2114 | RunFailed -- ^ statement failed compilation
2115 | RunException Exception -- ^ statement raised an exception
2116
2117 -- | Run a statement in the current interactive context. Statemenet
2118 -- may bind multple values.
2119 runStmt :: Session -> String -> IO RunResult
2120 runStmt (Session ref) expr
2121 = do
2122 hsc_env <- readIORef ref
2123
2124 -- Turn off -fwarn-unused-bindings when running a statement, to hide
2125 -- warnings about the implicit bindings we introduce.
2126 let dflags' = dopt_unset (hsc_dflags hsc_env) Opt_WarnUnusedBinds
2127 hsc_env' = hsc_env{ hsc_dflags = dflags' }
2128
2129 maybe_stuff <- hscStmt hsc_env' expr
2130
2131 case maybe_stuff of
2132 Nothing -> return RunFailed
2133 Just (new_hsc_env, names, hval) -> do
2134
2135 let thing_to_run = unsafeCoerce# hval :: IO [HValue]
2136 either_hvals <- sandboxIO thing_to_run
2137
2138 case either_hvals of
2139 Left e -> do
2140 -- on error, keep the *old* interactive context,
2141 -- so that 'it' is not bound to something
2142 -- that doesn't exist.
2143 return (RunException e)
2144
2145 Right hvals -> do
2146 -- Get the newly bound things, and bind them.
2147 -- Don't need to delete any shadowed bindings;
2148 -- the new ones override the old ones.
2149 extendLinkEnv (zip names hvals)
2150
2151 writeIORef ref new_hsc_env
2152 return (RunOk names)
2153
2154 -- When running a computation, we redirect ^C exceptions to the running
2155 -- thread. ToDo: we might want a way to continue even if the target
2156 -- thread doesn't die when it receives the exception... "this thread
2157 -- is not responding".
2158 sandboxIO :: IO a -> IO (Either Exception a)
2159 sandboxIO thing = do
2160 m <- newEmptyMVar
2161 ts <- takeMVar interruptTargetThread
2162 child <- forkIO (do res <- Exception.try thing; putMVar m res)
2163 putMVar interruptTargetThread (child:ts)
2164 takeMVar m `finally` modifyMVar_ interruptTargetThread (return.tail)
2165
2166 {-
2167 -- This version of sandboxIO runs the expression in a completely new
2168 -- RTS main thread. It is disabled for now because ^C exceptions
2169 -- won't be delivered to the new thread, instead they'll be delivered
2170 -- to the (blocked) GHCi main thread.
2171
2172 -- SLPJ: when re-enabling this, reflect a wrong-stat error as an exception
2173
2174 sandboxIO :: IO a -> IO (Either Int (Either Exception a))
2175 sandboxIO thing = do
2176 st_thing <- newStablePtr (Exception.try thing)
2177 alloca $ \ p_st_result -> do
2178 stat <- rts_evalStableIO st_thing p_st_result
2179 freeStablePtr st_thing
2180 if stat == 1
2181 then do st_result <- peek p_st_result
2182 result <- deRefStablePtr st_result
2183 freeStablePtr st_result
2184 return (Right result)
2185 else do
2186 return (Left (fromIntegral stat))
2187
2188 foreign import "rts_evalStableIO" {- safe -}
2189 rts_evalStableIO :: StablePtr (IO a) -> Ptr (StablePtr a) -> IO CInt
2190 -- more informative than the C type!
2191 -}
2192
2193 -----------------------------------------------------------------------------
2194 -- show a module and it's source/object filenames
2195
2196 showModule :: Session -> ModSummary -> IO String
2197 showModule s mod_summary = withSession s $ \hsc_env -> do
2198 case lookupUFM (hsc_HPT hsc_env) (ms_mod_name mod_summary) of
2199 Nothing -> panic "missing linkable"
2200 Just mod_info -> return (showModMsg (hscTarget (hsc_dflags hsc_env)) (not obj_linkable) mod_summary)
2201 where
2202 obj_linkable = isObjectLinkable (expectJust "showModule" (hm_linkable mod_info))
2203
2204 getBreakpointHandler :: Session -> IO (Maybe (BkptHandler Module))
2205 getBreakpointHandler session = getSessionDynFlags session >>= return . bkptHandler
2206
2207 setBreakpointHandler :: Session -> BkptHandler Module -> IO ()
2208 setBreakpointHandler session handler = do
2209 dflags <- getSessionDynFlags session
2210 setSessionDynFlags session dflags{ bkptHandler = Just handler }
2211 let linkEnv = [ ( breakpointJumpName
2212 , unsafeCoerce# (jumpFunction session handler))
2213 , ( breakpointCondJumpName
2214 , unsafeCoerce# (jumpCondFunction session handler))
2215 , ( breakpointAutoJumpName
2216 , unsafeCoerce# (jumpAutoFunction session handler))
2217 ]
2218 writeIORef v_bkptLinkEnv linkEnv
2219 dflags <- getSessionDynFlags session
2220 reinstallBreakpointHandlers session
2221
2222 reinstallBreakpointHandlers :: Session -> IO ()
2223 reinstallBreakpointHandlers session = do
2224 dflags <- getSessionDynFlags session
2225 let mode = ghcMode dflags
2226 when (mode == Interactive) $ do
2227 linkEnv <- readIORef v_bkptLinkEnv
2228 initDynLinker dflags
2229 extendLinkEnv linkEnv
2230
2231 type SiteInfo = (String, String, SiteNumber)
2232 jumpFunction, jumpAutoFunction :: Session -> BkptHandler Module -> Int -> [Opaque]
2233 -> SiteInfo -> String -> b -> b
2234 jumpCondFunction :: Session -> BkptHandler Module -> Int -> [Opaque]
2235 -> SiteInfo -> String -> Bool -> b -> b
2236 jumpFunctionM :: Session -> BkptHandler a -> Int -> [Opaque] -> BkptLocation a
2237 -> String -> b -> IO b
2238
2239 jumpCondFunction _ _ _ _ _ _ False b = b
2240 jumpCondFunction session handler ptr hValues siteInfo locmsg True b
2241 = jumpFunction session handler ptr hValues siteInfo locmsg b
2242
2243 jumpFunction session handler ptr hValues siteInfo locmsg b
2244 | site <- mkSite siteInfo
2245 = unsafePerformIO $ jumpFunctionM session handler ptr hValues site locmsg b
2246
2247 jumpFunctionM session handler (I# idsPtr) wrapped_hValues site locmsg b =
2248 do
2249 ids <- deRefStablePtr (castPtrToStablePtr (Ptr (int2Addr# idsPtr)))
2250 ASSERT (length ids == length wrapped_hValues) return ()
2251 let hValues = [unsafeCoerce# hv | O hv <- wrapped_hValues]
2252 handleBreakpoint handler session (zip ids hValues) site locmsg b
2253
2254 jumpAutoFunction session handler ptr hValues siteInfo locmsg b
2255 | site <- mkSite siteInfo
2256 = unsafePerformIO $ do
2257 break <- isAutoBkptEnabled handler session site
2258 if break
2259 then jumpFunctionM session handler ptr hValues site locmsg b
2260 else return b
2261
2262 jumpStepByStepFunction session handler ptr hValues siteInfo locmsg b
2263 | site <- mkSite siteInfo
2264 = unsafePerformIO $ do
2265 jumpFunctionM session handler ptr hValues site locmsg b
2266
2267 mkSite :: SiteInfo -> BkptLocation Module
2268 mkSite (pkgName, modName, sitenum) =
2269 (mkModule (stringToPackageId pkgName) (mkModuleName modName), sitenum)
2270
2271 obtainTerm :: Session -> Bool -> Id -> IO (Maybe Term)
2272 obtainTerm sess force id = withSession sess $ \hsc_env ->
2273 getHValue (varName id) >>= traverse (cvObtainTerm hsc_env force Nothing)
2274
2275 #endif /* GHCI */